Table 1.
Single cell analysis of the BCL-6 and IgVH genes in normal GC lymphocytes
| Cell phenotype | Mutated cells,
%*
|
Mutations, %†
|
||||
|---|---|---|---|---|---|---|
| BCL-6 | IgVH | β-globin | BCL-6 (742 bp) | IgVH (250 bp) | β-globin (395 bp) | |
| CD38+CD77− | 25/79 (31.6) | 11/14 (79) | nd | 40 (0.04)‡ | 141 (4.0) | nd |
| CD38+CD77+ | 12/37 (32.4) | 12/12 (100) | 1/32 (3) | 28 (0.07)§ | 184 (6.1) | 1 (0.004) |
| IgD+CD27− | 2/35 (5.7) | 2/16 (12.5) | nd | 3 (0.009)‡§ | 8 (0.2) | nd |
Number of cells harboring mutations over total number of cells sequenced. On average, >90% of the samples gave rise to a positive PCR product when the BCL-6 and β-globin gene were amplified; the amplification rate for the IgVH genes ranged from 20 to 70% in different experiments (average: 50% in centrocytes and naive B cells, 36% in centroblasts).
Total number of mutations found. Percentages were calculated by dividing the number of mutational events by the total number of base pairs analyzed (1,484 bp when both BCL-6 alleles were amplified). For the BCL-6 gene: centrocytes = 88,298 bp, centroblasts = 39,326 bp, and naive B cells = 31,164 bp.
Values displaying statistically significant differences are marked by identical symbols: ‡P = 0.017; §P = 0.010.
nd, not determined.